Patent attributes
An inkjet printhead chip includes a wafer substrate (116). Drive circuitry is positioned on the wafer substrate. A plurality of nozzle arrangements is positioned on the wafer substrate. Each nozzle arrangement includes nozzle chamber walls (132) and a roof wall positioned on the wafer substrate to define a nozzle chamber (134) and an ink ejection port (124) in the roof wall. A micro-electromechanical actuator (128) is connected to the drive circuitry. The actuator includes a movable member (130) that is displaceable on receipt of a signal from the drive circuitry. The movable member defines a displacement surface that acts on ink in the nozzle chamber to eject the ink from the ink ejection port. An area of the displacement surface is between half and twice a cross sectional area of the ink ejection port.
